His apology was formal and lacked sincerity.
After exchanging ritualistic greetings, we got down to business.
礼儀正しい means 'polite' or 'well-mannered' as a positive trait, whereas 儀礼的 can imply a more formal, sometimes hollow, politeness.
civil inattention; civil indifference
Compound of 儀礼 (ぎれい, 'ceremony, etiquette') + 的 (てき, '-like, -al'). The word 儀礼 itself is a Sino-Japanese term combining 儀 (ぎ, 'ceremony, rite') and 礼 (れい, 'propriety, thanks').